Topdressing method and topdressing device of potassium fertilizer for flue-cured tobacco

The invention provides a topdressing method and a topdressing device of potassium fertilizer for flue-cured tobacco, and relates to the technical field of crop cultivation. The topdressing method comprises the following steps: preparing the topdressing device, wherein the topdressing device is hollow and comprises a cone-shaped lower part and a cylindrical upper part, the top end of the upper partis provided with a lid, a scale line is arranged on the periphery of the upper part, and a plurality of osmotic holes are evenly distributed in the pipe wall of the topdressing device; before transplanting of the flue-cured tobacco, applying compound fertilizer; producing an arc-shaped ridge body after fertilization and covering a mulching film with the width of 90 to 100 cm after ridging; arranging the topdressing device at the midpoint close to the ridge body after the mulching film is covered; transplanting healthy tobacco seedlings to the midpoint of the arc-shaped ridge body, watering after transplanting and cov